.main_box{
  padding:45px 0 50px 0;
  box-sizing:border-box;
}

.head_box{
  width:100%;
  position: fixed;
  z-index:9;
  top:0;
  left:0;
}

#tab-bar.demo {
  display: flex;
  flex-direction: column;
}
#tab-bar .demoName {
  height: 40px;
}
#tab-bar .demo-preview-item .am-tab-bar {
  background-color: white;
}